Siemens QAX34.1 User Manual

CA2N1645en_02
30 Jun 2009

Building Technologies

1

645

DESIGO™ RX

Room unit with PPS2
interface

QAX34.1

for use with: – devices of the ranges DESIGO RXC, RXB, RXL, and RXA (PPS2)

– DESIGO PX Automation stations

1)

– devices with a PPS2 interface

 Room temperature measurement
 Rocker switch for adjustment of the room temperature setpoint
 Rocker switch for control mode selection (

/ Auto) and manual control of

the fan in fan-coil systems (up to 3 speeds)

 PPS2 interface to controller
 LCD with room temperature and control mode display
 Socket for commissioning and service tool or service terminal

Use

The room unit is used in rooms controlled by an individual room control system, to mea­sure the room temperature and for operation of the room controller. The functions of the
LCD display are determined by the controller. If manual fan-speed control is enabled,
the room unit is suitable for control of a fan-coil system.

It can also be used in conjunction with a DESIGO PXC… automation station

1)

.

The room unit incorporates a socket for a commissioning and service tool or service
terminal. This tool socket provides access via the PPS2 interface or via a bus system
(e.g. L

ONWORKS® bus) to the connected individual room controller.

1) If room units QAX32.1, QAX33.1, QAX34.1, or QAX84.1 are used in conjunction with a PXC auto­mation station, the room unit will show the request of the user and not the effective state.

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Siemens QAX34.1 – Room unit with PPS2 interface CA2N1645en_02
Building Technologies 30 Jun 2009

Ordering

When ordering, please specify the quantity, product name and type code.

Example:

30 Room units QAX34.1

Equipment combinations

The room unit is suitable for use in conjunction with all controllers which incorporate a
PPS2 room unit interface (e.g. DESIGO RX, DESIGO PX).

Mechanical design

The room unit is designed for surface mounting (with knock-outs for cable entry from
the top or bottom) or for mounting on a recessed conduit box with the cables connected
from the rear.

The unit comprises a housing and base unit, connected by releasable snap-fittings.

The base unit accommodates the screw terminals which have an integrated terminal
strip.

The housing accommodates a printed circuit board, room temperature sensor element,
setpoint adjuster, rocker switch for mode selection and fan speed selection, plug-in
connectors and a socket for the commissioning and service tool or service terminal.

Both the housing and base are made of plastic.

Base unit

Housing

80083

80084

Socket for the commissioning
and service tool or service
terminal

80166A

Room temperature display and sequence (heating or cooling)

Rocker switch for room temperature setpoint adjustment

Indication of current control mode or current fan speed

Rocker switch for mode selection and fan speed

The actual functions of the operator controls and indicators are determined by the con­troller (based on the selected application and associated parameters). The description
below covers all possibilities for these items.

The controller control mode can be selected on the basis of occupancy, using the
rocker switch on the room unit. The same switch can also be used for manual selection
of up to three fan speeds.

Operator controls
and indication

Note

Rocker switch for mode
selection and fan speed

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Siemens QAX34.1 – Room unit with PPS2 interface CA2N1645en_02
Building Technologies 30 Jun 2009

Pressing once in the direction of the left arrow switches one stage to the left, and press­ing once in the direction of the right arrow switches one stage to the right. The current
control mode or the manually selected fan speed is indicated in the display panel by a
horizontal bar below the associated symbol.

Position Fan speed control

1)

Control mode

1)

Fan controlled automati­cally by controller

The controller operates at the setback
setpoints (at night, or when room is un­occupied or occupied intermittently)

Fan controlled automati­cally by controller

Comfort mode (room occupied)

Manual, fan speed 1

Manual, fan speed 2

Manual, fan speed 3

1) For details of these functions, refer to the application description for the relevant controller range

Press the switch once to switch from a display of the current room temperature to a
display of the setpoint. Each further operation of the

+ or – switch raises or lowers the

setpoint by 0.5 K or 1.0 °F (the unit of measurement is determined by the controller).
The controller also determines the maximum adjustment range allowed.

In normal operation, the following may be displayed (depending on the controller con­figuration). For details of these functions, refer to the application description for the
relevant controller range.

Display element
(examples)

Description

Room temperature in °C (resolution 0.5 °C)

Room temperature in °F (resolution 1.0 °F)

Digital display of setpoint adjustment
(displayed only while relative adjustment is in progress).

Digital display and scale
(displayed only while absolute adjustment is in progress)

Control sequence: Cooling

Control sequence: Heating

Room units with mode and fan-speed selection enabled:
Fan speed 1: ON

In room units allowing mode selection only:
Auto: ON

Rocker switch room for
temperature setpoint
adjustment

LCD display